• Clinical and Experimental Pediatrics
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• v.49 no.10
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• pp.1042-1049
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• 2006

Purpose : This study was conducted to survey the preliminary data on risk behaviors and to identify the factors that prevent risk-behaviors in late adolescence. Methods : Freshmen(n=1,297) beginning the first semester in Korea University, Seoul, Korea completed self-administered risk behavior questionnaires, comprising 5 domains : demographics, smoking, drinking, drug abuse and sexual behavior. Results : The rate of smoking experience was higher in people having friends who smoke and the predictors of transition to current smoking were male gender, urban residence, friends' smoking, and nicotine dependence. The rate of high risk drinking was higher among students who are male and who had experience of heavy episodic drinking. The study group showed a low prevalence of narcotic users, but two-thirds of students could get medicine easily without prescriptions. The prevalence of sexual experience was 6.5 percent, and the sexual education was not a predictor of contraceptive behavior. The prevalence of homosexuality was 1.6 percent, and the rate of mostly heterosexuality was higher in female students. Conclusion : The main targets of youth health education should be campaigns aimed at atcessation of reinforcing risk behaviors and the development of a surveillance system for the prevention of chronic disease. These results can be used to find risk factors of health-risk behaviors among late adolescents.

• Journal of the Korean Magnetics Society
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• v.14 no.5
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• pp.192-195
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• 2004

Magnetic properties by exchange biased perpendicular magnetic anisotropy in [Pd(0.8 nm)/Co(0.8 nm)]$_{5}$/FeMn(15 nm) multilayers deposited by dc magnetron sputtering system are investigated. As inserted Pd layer of interface between [Pd/Co] multilayer and FeMn film, the Hex of perpendicular anisotropy was improved from 127 Oe to 145 Oe. But result of an experiment by thermal stability, the Hex of the case that an inserted layer was inserted in decreased from low 20$0^{\circ}C$ in about 5$0^{\circ}C$ more if not inserted. If Ta was a buffer layer, the experiment results along material of buffer layer, the H$_{ex}$ obtained the largest 127 Oe. And if Pd was a buffer layer, H$_{ex}$ obtained the largest 169 Oe. Also, the Hc in buffer layer of Ta and Pd obtained the largest 203 Oe and 453 Oe, respectively.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.8-15
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• 2007

최근 온라인 게임 시장이 급속하게 성장하고 있다. 온라인 게임은 컴퓨터 게임의 장르 중에 상당히 큰 비중을 차지하고 있으며, 많은 사용자들은 온라인 게임을 매일 즐기고 있다. 온라인 게임 시장이 커지면서, 온라인 게임 아이템의 거래 시장 역시 성장하고 있으며, 온라인 게임 아이템은 게임 안에서 거래가 이루어질 뿐만 아니라 게임 밖에서도 실제 화폐를 통해 거래되고 있다. 게임 아이템에 대한 경매 사이트가 국내뿐만 아니라 외국에도 존재하여 활발히 거래가 이루어 지고 있으며, 2004년에는 게임 아이템의 구매를 위해서 최대 8억 8000만 달러에 이르는 실제 화폐가 지불될 정도로 게임 아이템의 거래 시장은 거대하다. 이렇게 규모가 커진 게임 아이템 거래 시장은 학술적으로, 실용적으로 많은 중요성을 갖는다. 그러나 온라인 게임 아이템 거래에 대한 실증적인 연구는 많지 않다. 몇몇 온라인 게임 아이템 거래에 대한 연구는 게임 아이템의 권리를 중심으로 연구가 되었으며, 게임에 대한 많은 연구는 게임 아이템보다는 몬스터와 싸우는 것이나 게임 캐릭터를 만드는 것과 같은 게임 플레잉 설계에 집중하고 있다. 또한 전자 상거래 분야에서는 사용자들이 거래를 통해 최대한의 이윤을 얻기 위할 것이라는, 즉 외적 동기를 가지고 있을 것이라는 가정을 바탕으로 거래의 효율성과 거래 비용에 초점을 맞추어 연구가 진행되었다. 그러나 온라인 게임 아이템은 실용적인 성격뿐만 아니라 유희적 성격을 가지고 있기 때문에 온라인 게임 아이템 거래에서 사용자는 외적 동기뿐만 아니라 내적 동기도 함께 가지게 된다. 본 연구는 거래 비용이론과 몰입, 그리고 재미와 관련된 이론을 바탕으로, 온라인 게임 아이템의 거래 방식이 사용자의 지각된 재미와 사용자가 느끼는 거래비용에 미치는 영향을 실험 방법론을 통해 실증적으로 검증하였다. 본 연구의 결과, 거래에서 내적 동기를 가진 사용자는 게임 아이템 거래 의도에 지각된 재미가 거래 비용에 비해 더 많은 영향을 미쳤으며, 외적 동기를 가진 사용자는 게임 아이템 거래 의도에 지각된 거래비용이 지각된 재미에 비해 더 많은 영향을 미쳤다. 본 연구의 결과는 과거 대부분의 관련 연구가 거래 방법의 유용성만을 강조해왔던 것과는 달리, 거래 자체의 재미와 즐거움, 그리고 거래에 대한 몰입 등의 감성적 측면을 고려함으로써 거래 비용 이론을 확장했다는 데 이론적 의의가 있을 것이다. 또한 실용적 측면에서 게임 아이템 거래 방식을 어떻게 설정해야 사용자들에게 유용성과 더불어 재미를 제공해 줄 수 있는지에 대한 실질적인 가이드라인을 제시할 수 있을 것이다.

• Journal of the Korean earth science society
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• v.32 no.6
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• pp.525-536
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• 2011

In any applications using various types of spatial data, it is very important to account for the scale differences among available data sets and to change the scale to the target one as well. In this paper, we propose to use a geostatistical downscaling approach based on vaiorgram deconvloution and block simulation to generate fine-scale categorical thematic maps from coarse-scale fraction data. First, an iterative variogram deconvolution method is applied to estimate a point-support variogram model from a block-support variogram model. Then, both a direct sequential simulation based on area-to-point kriging and the estimated point-support variogram are applied to produce alternative fine-scale fraction realizations. Finally, a maximum a posteriori decision rule is applied to generate the fine-scale categorical thematic maps. These analytical steps are illustrated through a case study of land-cover mapping only using the block fraction data of thematic classes without point data. Alternative fine-scale fraction maps by the downscaling method presented in this study reproduce the coarse-scale block fraction values. The final fine-scale land-cover realizations can reflect overall spatial patterns of the reference land-cover map, thus providing reasonable inputs for the impact assessment in change of support problems.

• Journal of The Korean Association For Science Education
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• v.39 no.6
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• pp.799-807
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• 2019

The study was conducted to identify if the first-year program of science-focused school improved students' scientific core competency and science learning motivation. The first-year program of the science-focused school consisted of basic education in scientific inquiry, investigation, advanced experiment, and basic education in small research. There were a total of 262 participants in the program, and 169 students took three survey tests. Through the analysis of a group-based trajectory modeling, students were differentiated based on similarity of score changes. This study showed that the first-year program of the science-focused school significantly improved students' scientific core competency and science learning motivation. A group-based trajectory modeling found that about 40~60% of students saw the effects of the program. The students who chose the humanity track showed effects, while some students who chose the science-focused track did not show effects. A group-based trajectory modeling showed the methodological effects of identifying the change process of individual students. This study identified the positive effects of science-focused school policy statistically and is a meaningful example for analyzing the effectiveness of science-focused school programs.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.937-950
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• 2004

With growing population of internet and web applications, distributed environment is considered to be the standard architecture of application. A network management systems(NMS) is necessary to control and monitor the complex network resources for providing and sharing the heft quality service. We recognize the NMS as a standard infrastructure for supporting efficient networking and a separate commercial applications. We believe every resource including software, hardware and environment for the network management should be separated from special protocols, vendors and applications. Therefore, We need a standard network management system that is efficient and consistent because of the heterogeous network features. In regards to software development, software reuse through assembling and extending the reusable elements such as patterns and components assures to realize the best productivity and quality The component based development(CBD) methodology that can assemble black box though well defined interfaces makes it possible to develop easer and quicker applications and is proved as the best software development solution involved in construction, selection and assembly of components. In this thesis, we describe the architecture for the network management and identify, define and design the components through analysis and design in the network management domain and Identified components mapped to the component architecture. We also specify the component development and design and implement the component for developing the network management. Implemented components apply to the component repository system that register, retrieve and understand the components. We analyze, design and implement the entire network management system based on configuration, connection, performance and fault management through the pre-developed components.

• Journal of the Korea Concrete Institute
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• v.25 no.3
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• pp.271-281
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• 2013

The current seismic design code prescribes that a structural wall should be designed as a special shear wall when the building height is more than 60 m and its seismic design category is classified as D. However, the use of a special shear wall has a negative effect on constructability and economic efficiency. In the present study, the seismic performance of a special shear wall and a special shear wall with relaxed reinforcement detail was evaluated through a cyclic reversal loading test. The specimens were constructed to measure the results of the experimental variable regarding the reinforcement details of the special boundary element. Next, the seismic performances of a special shear wall structural system and that of a special shear wall structural system with relaxed reinforcement detail was evaluated by methods proposed in the FEMA P695. The cyclic reversal loading test results of this study showed that the performance of the shear wall with relaxed reinforcement detail was almost similar to the performance of a special shear wall and has the performance which requested from standard. The results of the seismic evaluation showed that all special shear walls with relaxed reinforcement detail are satisfied with the design code and seismic performance.

• Journal of Gifted/Talented Education
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• v.24 no.1
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• pp.63-80
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• 2014

The open inquiry is one of the representative learning approaches for gifted students. However, a gifted student should develop various complicated competencies to succeed in the open inquiry because of its complexity. This study develops a question list in accordance with each stage of inquiry so that the list could provide scaffolding in the process of open inquiry and students develop near-professional competencies and produce distinguished outcomes. For the purpose, we have reviewed various literatures related to research methodologies, academic writings, and learning of inquiry. Based on the review, we identified the open inquiry as cognitive, metacognitive, and sociocultural processes and set up the direction of the development of the question list. We also have elaborated the goals of the open inquiry, provided a model of the stage of inquiry, and developed the guiding question list belonging to each stage. As a discussion, we provided several noteworthy issues in the situation of when the list is used in the teaching of the open inquiry for the gifted.

• Journal of Korea Water Resources Association
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• v.51 no.6
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• pp.481-490
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• 2018

Recently, the spatiotemporal patterns of flood disasters have become more complex and unpredictable due to climate change. Flood hazard map including information on flood risk level has been widely used as an unstructured measure against flooding damages. In order to product a high-precision flood hazard map by combination of hydrologic and hydraulic modeling, huge digital information such as topography, geology, climate, landuse and various database related to social economic are required. However, in some areas, especially in developing countries, flood hazard mapping is difficult or impossible and its accuracy is insufficient because such data is lacking or inaccessible. Therefore, this study suggests a method to delineate large scale flood-prone area based on topographic factors produced by linear binary classifier and ROC (Receiver Operation Characteristics) using globally-available geographic data such as ASTER or SRTM. We applied the proposed methodology to five different countries: North Korea Bangladesh, Indonesia, Thailand and Myanmar. The results show that model performances on flood area detection ranges from 38% (Bangladesh) to 78% (Thailand). The flood-prone area detection based on the topographical factors has a great advantage in order to easily distinguish the large-scale inundation-potent area using only digital elevation model (DEM) for ungauged watersheds.

• Journal of Korea Water Resources Association
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• v.51 no.6
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• pp.503-514
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• 2018

In recent, the hydrological regime of the Mekong river is changing drastically due to climate change and haphazard watershed development including dam construction. Information of hydrologic feature like streamflow of the Mekong river are required for water disaster prevention and sustainable water resources development in the river sharing countries. In this study, runoff simulations at the Kratie station of the lower Mekong river are performed using SWAT (Soil and Water Assessment Tool), a physics-based hydrologic model, and LSTM (Long Short-Term Memory), a data-driven deep learning algorithm. The SWAT model was set up based on globally-available database (topography: HydroSHED, landuse: GLCF-MODIS, soil: FAO-Soil map, rainfall: APHRODITE, etc) and then simulated daily discharge from 2003 to 2007. The LSTM was built using deep learning open-source library TensorFlow and the deep-layer neural networks of the LSTM were trained based merely on daily water level data of 10 upper stations of the Kratie during two periods: 2000~2002 and 2008~2014. Then, LSTM simulated daily discharge for 2003~2007 as in SWAT model. The simulation results show that Nash-Sutcliffe Efficiency (NSE) of each model were calculated at 0.9(SWAT) and 0.99(LSTM), respectively. In order to simply simulate hydrological time series of ungauged large watersheds, data-driven model like the LSTM method is more applicable than the physics-based hydrological model having complexity due to various database pressure because it is able to memorize the preceding time series sequences and reflect them to prediction.